a part of a sail that is rolled and tied down to reduce the area exposed to the wind.

verb (used with object)

to shorten (sail) by tying in one or more reefs.
to reduce the length of (a topmast, a bowsprit, etc.), as by lowering, sliding inboard, or the like.
to pull (old oakum) out of seams, as with a rave hook (often followed by out).

Origin of reef

1350–1400; Middle English refe (noun) < Dutch reef
Related formsun·reefed, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for reefing

Historical Examples of reefing

  • In reefing top-sails, the cry when the weather earing is passed.

    The Sailor's Word-Book

    William Henry Smyth

  • The order for men to come in from the yards after reefing or furling.

    The Sailor's Word-Book

    William Henry Smyth

  • The order to come in from the yards when reefing, furling, or other duty is performed.

    The Sailor's Word-Book

    William Henry Smyth

  • Archy had several times been aloft, but had never assisted in reefing.

    Archibald Hughson

    W.H.G. Kingston

  • Do you intend to spend the remainder of the watch in reefing that topsail?

    The Rover's Secret

    Harry Collingwood

British Dictionary definitions for reefing




a ridge of rock, sand, coral, etc, the top of which lies close to the surface of the sea
a ridge- or mound-like structure built by sedentary calcareous organisms (esp corals) and consisting mainly of their remains
a vein of ore, esp one of gold-bearing quartz

Word Origin for reef

C16: from Middle Dutch ref, from Old Norse rif rib 1, reef ²




the part gathered in when sail area is reduced, as in a high wind


to reduce the area of (sail) by taking in a reef
(tr) to shorten or bring inboard (a spar)

Word Origin for reef

C14: from Middle Dutch rif; related to Old Norse rif reef, rib 1, German reffen to reef; see reef 1


noun the Reef

another name for the Great Barrier Reef
another name for the Witwatersrand
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for reefing



1660s, "take in, roll up" (as a sail on a ship), from reef (n.2). Related: Reefed; reefing.



"rock ridge underwater," 1580s, riffe, probably via Dutch riffe, from a Scandinavian source, cf. Old Norse rif "ridge in the sea; reef in a sail," literally "rib" (see rib (n.)).



"horizontal section of sail," late 14c. (mid-14c. in rif-rope), from a Scandinavian source, cf. Old Norse rif "reef of a sail," probably a transferred use of rif "ridge under the sea; rib" (see rib (n.) and cf. reef (n.1)). German reff, Swedish ref, Norwegian riv, Danish reb likely all are from the Old Norse word.

Online Etymology Dictionary, © 2010 Douglas Harper

reefing in Medicine




Surgical reduction of the extent of a tissue by folding it and securing with sutures.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

reefing in Science



A strip or ridge of rocks, sand, or coral that rises to or near the surface of a body of water. See more at coral reef.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.